Limited design freedom with the desired material.

3D-printed tools with Freeform Injection Molding, which enable food-safe materials.

The perfect bottle cap from PepsiCo. The material used for this project is PepsiCo blue HDPE.

The bottle cap was designed to resemble the early PepsiCo bottle caps, and the challenge lies in the internal design to ensure a proper fit through molded threads.

Once the design is complete, the digital design (STEP file) is converted into a mold design by turning the part into a cavity in a block of material and then adding the inlet(s) and the first vent.

The two-part first draft enables quick visual quality assurance.

The moulds were printed with a resolution of 100 μm to ensure good mould quality and at the same time optimize the setup for fast production.

The parts were formed on a 50-ton press. However, the molds work hand in hand with each installed basic injection molding unit. The cycle time per part was about 5 minutes, and the cooling time after each shot was 1 minute.

The alkaline Nexa3D solution was used to demold these parts in just one day.

This time can be optimized by redesigning the mould, by removing part of the mould before demoulding or by removing the part directly, if possible

• Designing the mold is a simple process; similar to building a mold box around the design, and then it becomes a cavity.
• The blue HDPE material from PepsiCo filled the molds well in the first rounds of testing.
• Optimization of the demoulding process is recommended for the next iterations. The more material that can be removed or reused, the faster the process.
• Standard material data was used for shaping, settings, pressure, temperatures, etc.
• For most team members, early hands-on testing to verify assembly and performance using parts that come out of the mold first is valuable. This includes materials, design, processes and compliance with regulations.
• If required, the free-form injection molding process enables further iterations on the same day.